Clinical Manifestations. The neonate displays multiple contractures, dislocated joints, adduction/internal rotation of the upper limbs (“waiter’s tip” position), and stiff, diamond-shaped lower limbs. The deformities are usually bilateral, showing variable symmetry and involvement of the limbs. Active and passive range of motion is dramatically limited, with the joints characterized by noticeably absent skin creases. The skin is thin and smooth, and subcutaneous tissue is scanty. Muscle atrophy is striking. The bones are thin and spindly, and fractures, particularly in the lower limbs, may occur at delivery. Soft tissue webbing may also be evident.

In classic arthrogryposis, intelligence is normal. Patients display normal facies, no visceral abnormalities, retained bowel and bladder function, and intact sensation. Most remain ambulatory.

Arthrogryposis is associated with other conditions such as tuberous sclerosis, neurofibromatosis, myelodysplasia, and lumbosacral agenesis. Freeman-Sheldon syndrome, also known as “whistling face” syndrome, has many features similar to arthrogryposis but also with a characteristic puckered facial expression.

Treatment. In the newborn period, the focus of management is on treating both the deformity and the muscle weakness. Vigorous stretching is recommended to correct the rigid deformities, but care should be taken to avoid undue force because of increased fracture risk. The ultimate end goals are to allow for independent ambulation as well as independent upper extremity function in performing activities of daily living.

Deformities of Upper Limb. In the neonatal period, management of upper limb deformities comprises splinting and vigorous passive range-of-motion exercises. If the elbows are fixed in flexion, early exercises and splinting may be sufficient. More commonly, the elbows are fixed in extension and surgical release and/or muscle transfer is necessary. Although the wrist and hand are usually severely involved, patients have adequate function. Regardless of the surgical procedure planned, the end goals should ensure bimanual hand function, with the shoulders and elbows allowing for the hands to work at tabletop level.

Deformities of Foot. The foot is nearly always involved in arthrogryposis; most common is rigid clubfoot (equinovarus). Surgical posteromedial release of the contracted structures in early infancy is necessary to allow correct positioning of the foot. Patients with severely affected feet are treated with bracing and splinting in the growth years to maintain the surgical correction. Recurrence is still common despite long-term postoperative orthotic treatment.

Deformities of Knee. The knees are commonly held in stiff extension. Although rare, flexed knee deformity is more troublesome in limiting ambulation. Early passive range-of-motion exercises, supplemented with serial casting/splinting, may be necessary to restore motion. With severe hyperextension deformity (sometimes leading to frank dislocation), surgical release or lengthening of the contracted quadriceps muscle is needed. Flexion deformity of the knee rarely responds to conservative treatment and often requires early surgical release of the posterior capsule and hamstring muscles. Perioperatively, careful wound closure and postoperative skin monitoring are essential, especially while serial casting/splinting.

Deformities of Hip. Hip involvement is characterized by two types: soft tissue contractures and dislocations. Soft tissue contractures are evident in the neonatal period and can result in concurrent pelvic obliquity and scoliosis. Management includes early passive stretching, splinting, and surgical release. In the child with mild involvement, dislocated hips can be managed with the standard techniques used in congenital dislocation of the hip. More commonly, however, the hips are both stiff and dislocated and radiographs reveal advanced and adaptive changes similar to those seen in the older child with classic congenital dislocation of the hip. Surgery is generally performed in the first year, typically consisting of an open medial surgical reduction procedure, because closed reduction of the hips is largely unsuccessful. In the older child, surgery consists of an open anterior surgical reduction ± a femoral shortening osteotomy.